Are Swedish swingers a risk group for sexually transmitted infections?

The aim of this study was to investigate whether Swedish swingers constitute a risk group for sexually transmitted infections (STIs). Two swinger clubs were invited to participate. At swinger meetings, members were offered an STI sampling kit and a questionnaire. Samples were analyzed for Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, and Trichomonas vaginalis using a multiplex real-time polymerase chain reaction assay. In total, 235 swingers participated (118 women and 117 men). Urogenital C. trachomatis prevalence was 1.7%. Urogenital M. genitalium prevalence was 7.6% for women and 4.3% for men. No one tested positive for N. gonorrhoeae or T. vaginalis. For women, the mean number of unprotected temporary sex partners within the last 12 months was four men (range 0-35) and three women (range 0-50). Among men, the mean number of unprotected temporary sex partners within the last 12 months was five women (range 0-50) and 0 men (range 0-10). During vaginal sex, 46.6% women and 38.5% men always used protection with a temporary sex partner. Swedish swingers did not seem to have an increased prevalence of STIs. However, there was high-risk sexual behavior with unprotected sex and multiple sex partners, thereby making them a vulnerable group for acquiring STIs.